I guess it's hard to blame them. I would wager that the majority of dryers that get scrapped have nothing wrong with them at all, they're just cosmetically out of style and/or the matching washer failed and the owner bought a new matched set. A large majority of those that are actually broken probably have very simple faults.
Not that there are too many faults that can occur in a dryer that aren't simple, there's very little to the whole machine. Even most of the recent stuff with fancy looking control panels is the same internal parts as one that is 40-50 years older. I recently fixed the fancy "electronic" infinite temperature control on my own dryer, turns out it's nothing more than a variable resistor in series with a resistor built into the cycling thermostat on the heating element, 240V fed directly through the variable resistor controls how hot the resistor in the thermostat gets, which shifts the temperature it cycles around. It's a slight twist on the standard pushbutton low/hi setup that dryers have used since at least the 1950s.
A few months ago worked on the moisture sensor on a friend's dryer and found it's nothing more than a triac switch that cuts power to the timer motor each time wet clothes pass over the sensing contacts. The wetter the clothes, the lower the duty cycle of the timer motor and the longer the dryer runs. Clever really, but 1970s technology in a mid 2000's dryer. In that case the triac had failed shorted so the timer was never pausing and the clothes wouldn't get dry before it ran out.
I don't do this for a living but when word gets around that you're good at fixing stuff, people come out of the woodwork with broken stuff.